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Diffstat (limited to 'packet-lapd.c')
| -rw-r--r-- | packet-lapd.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/packet-lapd.c b/packet-lapd.c new file mode 100644 index 0000000000..a0b98e9fe1 --- /dev/null +++ b/packet-lapd.c @@ -0,0 +1,154 @@ +/* packet-lapd.c + * Routines for LAPD frame disassembly + * Gilbert Ramirez <gram@xiexie.org> + * + * $Id: packet-lapd.c,v 1.1 1999/11/11 05:36:05 gram Exp $ + * + * Ethereal - Network traffic analyzer + * By Gerald Combs <gerald@zing.org> + * Copyright 1998 + * + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#ifdef HAVE_SYS_TYPES_H +# include <sys/types.h> +#endif + +#include <stdio.h> +#include <glib.h> +#include <string.h> +#include "packet.h" +#include "xdlc.h" + +/* ISDN/LAPD references: + * + * http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/isdn.htm + * http://www.ece.wpi.edu/courses/ee535/hwk11cd95/agrebe/agrebe.html + * http://www.acacia-net.com/Clarinet/Protocol/q9213o84.htm + */ + +int proto_lapd = -1; +int hf_lapd_address = -1; +int hf_lapd_sapi = -1; +int hf_lapd_cr = -1; +int hf_lapd_ea1 = -1; +int hf_lapd_tei = -1; +int hf_lapd_ea2 = -1; +int hf_lapd_control = -1; + +static const value_string lapd_sapi_vals[] = { + { 0, "Q.931 Call control procedure" }, + { 1, "Packet mode Q.931 Call control procedure" }, + { 16, "X.25 Level 3 procedures" }, + { 63, "Layer 2 management procedures" }, + { 0, NULL } +}; + +void +dissect_lapd(const u_char *pd, frame_data *fd, proto_tree *tree) +{ + proto_tree *lapd_tree, *addr_tree; + proto_item *ti; + + guint16 address, cr; + + gboolean is_response; + + if (check_col(fd, COL_PROTOCOL)) + col_add_str(fd, COL_PROTOCOL, "LAPD"); + + address = pntohs(&pd[0]); + cr = address & 0x0200; + + if (fd->pseudo_header.lapd.from_network_to_user) { + is_response = cr ? FALSE : TRUE; + if(check_col(fd, COL_RES_DL_DST)) + col_add_str(fd, COL_RES_DL_DST, "User"); + if(check_col(fd, COL_RES_DL_SRC)) + col_add_str(fd, COL_RES_DL_SRC, "Network"); + } + else { + is_response = cr ? TRUE : FALSE; + if(check_col(fd, COL_RES_DL_DST)) + col_add_str(fd, COL_RES_DL_DST, "Network"); + if(check_col(fd, COL_RES_DL_SRC)) + col_add_str(fd, COL_RES_DL_SRC, "User"); + } + + + if (tree) { + ti = proto_tree_add_item(tree, proto_lapd, 0, 3, NULL); + lapd_tree = proto_item_add_subtree(ti, ETT_LAPD); + + ti = proto_tree_add_item(lapd_tree, hf_lapd_address, 0, 2, address); + addr_tree = proto_item_add_subtree(ti, ETT_LAPD_ADDRESS); + + proto_tree_add_item(addr_tree, hf_lapd_sapi, 0, 1, address); + proto_tree_add_item(addr_tree, hf_lapd_cr, 0, 1, address); + proto_tree_add_item(addr_tree, hf_lapd_ea1, 0, 1, address); + proto_tree_add_item(addr_tree, hf_lapd_tei, 1, 1, address); + proto_tree_add_item(addr_tree, hf_lapd_ea2, 1, 1, address); + } + else { + lapd_tree = NULL; + } + + dissect_xdlc_control(pd, 2, fd, lapd_tree, hf_lapd_control, is_response, TRUE); + + /* call next protocol */ +} + +void +proto_register_lapd(void) +{ + static hf_register_info hf[] = { + { &hf_lapd_address, + { "Address Field", "lapd.address", FT_UINT16, BASE_HEX, NULL, 0x0, + "" }}, + + { &hf_lapd_sapi, + { "SAPI", "lapd.sapi", FT_UINT16, BASE_DEC, VALS(lapd_sapi_vals), 0xfc00, + "Service Access Point Identifier" }}, + + { &hf_lapd_cr, + { "C/R", "lapd.cr", FT_UINT16, BASE_DEC, NULL, 0x0200, + "Command/Response bit" }}, + + { &hf_lapd_ea1, + { "EA1", "lapd.ea1", FT_UINT16, BASE_DEC, NULL, 0x0100, + "First Address Extension bit" }}, + + { &hf_lapd_tei, + { "TEI", "lapd.tei", FT_UINT16, BASE_DEC, NULL, 0x00fe, + "Terminal Endpoint Identifier" }}, + + { &hf_lapd_ea2, + { "EA2", "lapd.ea2", FT_UINT16, BASE_DEC, NULL, 0x0001, + "Second Address Extension bit" }}, + + { &hf_lapd_control, + { "Control Field", "lapd.control", FT_UINT16, BASE_HEX, NULL, 0x0, + "" }}, + }; + + proto_lapd = proto_register_protocol ("Link Access Procedure, Channel D (LAPD)", "lapd"); + proto_register_field_array (proto_lapd, hf, array_length(hf)); +} |